SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99651e4af54ec33f4fe93340c23e367daaaa72e2edd6865244d80bca0c85528d' 
  AND token = 'JcRz4npLHXUqj3dqRQVsLPADpOD5JBRMPvjZlg+Vv/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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