SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65643c215771dc38615a98a620d9c3969adc360689f4eba5724841840875ed8f' 
  AND token = 'itgB2g1dcCYEazU3LJnR3XDD0p6xOhQrqc2RBcPLU0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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