SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78d6fabdef04c12cc5664d20a0123bd470a7f9e0344fe558759a52bdeab567e5' 
  AND token = 'RqSz1YSj9TQuvRwhxc5Nuhq0+1wN63YydGLKWfRZq44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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