SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '770a7654e30c5031d30b0d776cd3771d1d5dd40b9b1fbb1dfcdf2481a58c0353' 
  AND token = 'ZFqBsY8kGv1a2y9VSU4g1BCYMpzkjaKrxXAQhUAzTPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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