SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63c8d4bd647f1b1ecf0de06f91a2f53445f229e779d19ba3bf8256ce0b5c1e3f' 
  AND token = 'JP2tsoRZTpdBG6vngjR+/wsQQQlSRB4UgQjbWmWgWLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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