SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c57257e30729cf031db0fc0907eb72ca9fdee1640aad2b04cd392a6f88ca4274' 
  AND token = 'YS5DndtPeOTpXH4s+67vK/lIkIKOmKnx5RqPSHwBnlQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}