SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7f556f225799859c64477c7f0847ff665bf9d7194d194a038114210499edf1f4' 
  AND token = 'xBCpyxcCuULjUceL+MIwcwXcHuF65M8u4Y3dms9IODg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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