SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '644c22949218686951db9726c496c4bf5e350f850e7896096d64b30ea74f3146' 
  AND token = 'YW8LJ6zlUyz4AhvosKWlmUFiPoLVQ4gKNIKO85wxD5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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