SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b1cc50d6d980a4871a031a29e2917441a7630dcf30706e8a86d852cfd66d1d03' 
  AND token = '/Ax/ZWj8C87qStqyMXXh8ENaEvrJNUcykSMIWWOCi2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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