SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f7799f9db948c4f75536f7f9d5d6e98ca76fa0d54e1e42fc8041d969943487b3' 
  AND token = 'ovQUwgOqRoFrN0bIz6aBYZ308mxoV+WnCjHH4ZMjpJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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