SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '880ecb85985f4140561b93ab9f1e4a821828d115dcca73574d1c4f8fb262122f' 
  AND token = 'QEAIh4nl8jtquihqP/ntAzOFZCVxScS3DQVnPBJA7L8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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