SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12d0a153b2d36ebbf2212cd4334343ad31d20c094294ff4576b2bcd3d77e2ae3' 
  AND token = '+Tnctd1GyvcMaTd4KOPQhPUUpZdJgf1CM4VkBiNcufA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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