SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0019598c801556cbaea0ce82d8304d71abc40b9034fee52086c8902e30406f12' 
  AND token = 'i0Wq6hFxMrzP830jSTSumzKg00TlPQgOLC9me1YyV48=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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