SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15358ebce109c81ef2787286eaceb3d52a0cb7f6b5abc044b1ca2b12f12256b4' 
  AND token = 'MhUI7JefcRScU00ATb9jMS6OBUoovLNPNsbTd8mV7lc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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