SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '046e74deeb54af7cc74c082ed6a69088a69b196f8a546365cfd58d22f6b62a86' 
  AND token = 'rlXgXH0grRBRAGnPis0tt02011e89g8SlT406Vbqtrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}