SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '992d37ecb48684dc97639cbf1f15c76fd25250751156aea802854f7c57d1c729' 
  AND token = 'n4CYJLH2dk95k/XlAfI+NEglhngW7WsSZmNdiY7WIzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}