SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fce3abb70d65f7901d0844cf944d178dde800275cd798eaf24b3067853fe1c4e' 
  AND token = 'maaKM4ayuWlheptwSZu1g4bAhyY1EvcetWvvxMHLgxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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