SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5006e409835f50c8669b263fadbbe8af511bb7a1aad3a531d4d0d5f9899c797' 
  AND token = '1OsyXgYGSo6Hx8ZXJJyprzTgkyB2EhjWQr0VIKyB3y4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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