SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f0f2ce674f2925c83244c8dd887d4db15b5d206a9ed6c8731248f169852b8ef' 
  AND token = '3PiqnFu3+a08xcz1zpfCC/isbwZfNxGgqpU/MZruCQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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