SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5931467c8d21927fc84b3c91365ffd546167980f345a0fee14356bb98cb8aab0' 
  AND token = 'yBELGJwqjJImAA6zwWY6yrCd3UMcTb4pbhtE9phXs9M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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