SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d8569b050a1da3e728ce6592603d96011376537490e5d7fcb5fd192219a44b0' 
  AND token = 'wGlEUInh23BDp/IyRIoBHxqYVjfcRDagO82ZuBDcZ7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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