SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57519b21aceac77b93dd743d0571c5880f678c0ad5b6c445717bea3d15476c27' 
  AND token = 'mJ/qI4KYEr7zvcUuOF2Fz1WuCSEXTOgxYxpadLIjwqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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