SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c164eff8e2133aee79764a49baeb6394092202ae31bb49fe5ddf0204cb630a1' 
  AND token = '7PBwvKd45o+JKqXsRjs0ZhAMl0W+/jl6qm/SujL+Ymo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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