SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fc40ffd4f93b81314357376e63a6705e67c3d66a8220bff2e8273286cbde76e' 
  AND token = 'vjMTf+f3zng1loj+nFVSvqhkhCEGCKx0Ylh/W8g/syM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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