SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46e9328bcce7031bc16b80f41edfabffed500c644876db41d09f83fdaa56562b' 
  AND token = 'Y44JsvWzAAofMi3WwpvLsBld0n0TpwuJSu4udL2ntq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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