SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9618f92d778d97be10795f50be1da1ec756aa23e672de55bafa47bad27211e75' 
  AND token = 'J2FVSk4/5bg4IbxWrBOYGJJXuiO7hSFjA3S2XREdGq8=' 
  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"
    }
  }
}