SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef0a8aac184cac4d12b51624630ef0b3a586899422365152ea78f557dddc1187' 
  AND token = 'ioVPPo104xQbUjRuOpAVLF7+xQjo6EFNTiInv1tVy3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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