SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fa2a18f24ed24c870fc77f44815d318fda5575f26bded8756389e1af5f97945' 
  AND token = 'X+tFvwCTMIrgvMLaEK37tkAZ+qz4BfWhDs+JNuWfjIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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