SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffaf71ec3f300b1676b2456264491b1d118607d5c280ecc486e3ed13662c9d75' 
  AND token = 'OtiIv8ZTh+4uOpnniu3nSljTYaqJG77Wyz8f3n6xqBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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