SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c20b5af76057c707ad2926a2ebd7cd0479c8cf45c3a20b1db5d0fdc0a1aaee7' 
  AND token = '0sgdhGL1ZNLS/vwdXcAGn6ksKqB4al22BRZ+cZ4eSMY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}