SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dce5fcc0f8da03077f9902476a8a1c61b2fbd475219b9ed067d122e20716ccd3' 
  AND token = 'wfoRSl0c9nbt4ApXGo747bUyOcmQ+FRLdhj0vYIvQLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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