SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c96301b6f9aacf787ea94d120bf0e29fd3601d840817a403cf9db2615b78e8c0' 
  AND token = 'Vyc1OuQLxmhLSoPok987HTJn889/U7z2xMpSjNm08CY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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