SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f943b4d04b0e936c756ee6bca10d669dd9e186d831f75dd0204831600c7306f7' 
  AND token = 'VbUBFSjOAZrD4GHtz1my8BDvLaQ9L4GAfgYi0s48L4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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