SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '26d4d922dcee3432e05136e4320546f9a7e8bdab6dea408af14efe830d6c05ec' 
  AND token = '3Dc/7FJUziqccG8v+sboxoE2upSNMSg3cdNF0a4EJRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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