SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f8469510fd1b1fbe808b39bd7edf2a682d26ce61f168fe190dd4241aac66549' 
  AND token = 'kAmeYs9F9QpK8lG+Yeeks7D9khUK4ndYEuLvmUugWgc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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