SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '59bd42896396b232a24a0ef28af6542d8424556e044765ed65c6e6624cbd14d4' 
  AND token = 'sNl687DHlDmSsevl8pbkGQiios2dXdXUdvg220Xku6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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