SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abec2f136923003a0db14e7f0e0a7ddb30bb9fea56b46b877f5d95579246c376' 
  AND token = 'VQxvWc/sQmSuMjNCKLu+2gz+USNjZTJGuntZ2zfW1y0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}