SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a2a83ffb4a411066e2a5c3f8bf640c5c01ddb3b3eae20399f38eb74591f88c0' 
  AND token = 'bZLZa4BQJ9HIzwgpucegClDIhSzSQEJ1KMEn9FY+Ioc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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