SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '02435ef3774c280b7b44cde2a164951832cf552fa43008ebc79e5bd16dc86f5a' 
  AND token = '+1xhkEjvIWPsBNeW+1kOKlwTaQjkUFFV+fY29Ai1smQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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