SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7cc2a68559bd2c02fba29fcd100e7ec1559cdace0b2e4d3b77f8a87682c07e48' 
  AND token = 'NlPLXwrFzcZjnpnJ1Dt+aAhkmMXv84Htx7egSK/azUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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