SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30c39b47ad136edf0f9d85d6edb769ba90c222c38d9dceb5c7f50a0aa55e816c' 
  AND token = 'Y2VLiDsqCdJvfFCEPFgXNOawQsqBPPFc7ACqKIuLdgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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