SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd0e1a346ddc9511f9b9ca2b3ae7b528d7e809b9975724b38796b1173c3806ca' 
  AND token = 'Z4+5dQeZQ8Vst78NcCa8QpbLJlpHwJW3K2K5k3n/iIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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