SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd53f13b5e2468b1842bb3d24882a49d2e4d7e24688bdfbb27b9fedbf8741545' 
  AND token = 'YaYUFTYjf1en1Zlu/R6RAE020FEEyXyDhu0UxivTyeU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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