SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '274204f6534fb96581777adc6b8e4ee0b3c5744a2a1c18c57523d833f14e645e' 
  AND token = 'gZJxnNCXCOBsnjUP4AEa8sCLkvZLTMIp6NLrWhruqc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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