SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7950e1c88439aa6ffd11f2582aeb533378433da119ca6ede04198eb7460c2296' 
  AND token = 'HEPg/sqx/lDQYy2m5lVEMSFoWgp+elkiCrO1QoeNdf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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