SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ddfd7c04c23b5a505b05f580ee9cf3eb68579d7fc990db79ecabbfe1e0f639d' 
  AND token = 'NNIDSmTQHn1mylAut6Xm++EfZQ9+nEx758CgdV6PClE=' 
  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"
    }
  }
}