SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02cc0eecbc5a24e422daa818e00e1d96d186fcedfc7259576d4ffb8dd45e1d4f' 
  AND token = 'ArdPqtQjAVXFE47YwF0tYqXPwzttXMPaKEBRq54euNk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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