SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ad163e9fe65e72c5194598bbc4708279f39b488e32592558cc363af64576c12c' 
  AND token = 'jUgxf0PQCA+Hd6HRn160VgDqnLpZ1Fl2G03aAk9ehug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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