SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab4a756bc9feb282c9edb42cee35a37a7614ea125985fe06433b326e113833be' 
  AND token = 'bjJ8oLfgQUkaA6Ph0dHkkaj/63q7NrTW6j5lHTTzzxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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