SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c97f9725e88801d26c5cd6b23584631f46ae6ee26e91579c5a542e519a0896c7' 
  AND token = '+fXfkIpwacaT2oNdyHj72R+p9DU1W3M3+gOYdASkUgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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