SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dab0a68271e77004d0491207b586af8165bc02a5adf8a63beeaf36baa5e1d90c' 
  AND token = 'zNERqM4dpHXnnFWYkaoEvYiAUdPFPAcNfahJPrEHmhc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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