SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f574faa677dda06339ec7cf6df7ff44f3d44e2bc8eeb6d34a0e8f9319e732190' 
  AND token = 'XrcyJMO+1D4rLEWmALN+Xc5bO0g2y1ByfliItBpW1Ng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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