SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af85d50021e57b9f329ddfacd62b8009a694f733388ab2582e405db1f5636596' 
  AND token = 'BeeBllIDSSiDz0SWYLkrAOiXbOQ2Znf8DsH+ZKzmmrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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