SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84bbf43193fb88e2b261d4a2e478fba63d1ce25398b7f6a3bc4202f0c0ea3e12' 
  AND token = 'yBHV59NbkAzevqtHdTQOAhDkRMVY9YNCYsE/hiZGn/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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