SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9fe217c04c0b3af32bec0fa5bd873c41eb51dcebc5ab51399c2565618284283' 
  AND token = 'M5SPK5VTNFoceu3Ksp2NTbHNQlSdc8tZRLl6TaKL9VA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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