SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0320bd3d94783fe4852478e539bb8028e62f27b41fd360e3f30e360fce87c54' 
  AND token = 'n7XeGzGWay7oBUnB8v+Onuql420KT2vDmbbHCDhmBHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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