SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30c44d49140eed8370a5a94378fecb1674a124768d1ac4c9dd5f8a95dd512556' 
  AND token = 'P4U+6aqXK6mdcS6aa1z2hEbBg0YKqrFxM+yeTcQtfk8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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