SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67da8acfbbfee7af823d90038e8bd88a40f42fdc9e55c9f444972fc7448bad52' 
  AND token = 'RM0gOqvtw1oCpZmrBnredyKI4FScbq7i1TugwxRExbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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