SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2fd804f6b134a91e876c824280632488c68d330c5cbaa169631a5138e7861b2' 
  AND token = 'AOeXf74o4C89c/XB/wwci/sIU27xtBW14l+3CVMuAgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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