SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '73674068bd6d1cf0956cfa759b8839b1cfc514ae423c0721ecb8abf8eb652f54' 
  AND token = 'LesXR2WQbb3TCiDGARhOC4Zy/lMvMiI1uPYGbcumPeU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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