SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efe45f74409eb56bbcbd50a60391868dda0ddae03a15243872c700ed0618aafa' 
  AND token = 'lhDEMbwg0GKTzxpEeSQQ25JO6v9cohkS+9zGD6NSs60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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