SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99f19e6342c1e7832c4d504e9fcdf2549d4741e5d977abbc5ba7adf887e56aa0' 
  AND token = 'bZUONspY86H00sMeVGxSllcIRkVCdJbaUmABvTHH+24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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