SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9d84934ca4688d9758322dcaec271eb04ca85be351bc5809fa2182cb3e66c5e' 
  AND token = 'vbkSLPR0WWxCXOaT6yYYMgBYCK22FMlrrYtAri4KIhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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